Darwin’s Critics: Then and Now


(system) #1

This is a companion discussion topic for the original entry at https://biologos.org/blogs/ted-davis-reading-the-book-of-nature/darwins-critics-then-and-now

(Bill Cole) #2

Hi Ted

My sense is that natural selection being the primary cause of diversity is rapidly losing steam as evidenced by the desire to extend the modern synthesis in the recent meeting at the Royal Society and discussions with biologists.

If we take Behe’s flagellum as an example it very hard to imagine 100k nucleotides becoming organized to build this motor by a trial and error process. If this is an evolutionary step to evolve mobility in bacteria what does this say about the evolution of complex multicellular organisms.


(Peaceful Science) #3

This actually is not problem for evolution. Exaptation, co-evolution, and the nature of sequence space mean that the flagellum does not not present any problems to current understandings of evolution.

This however, is a more interesting point. @TedDavis, is that really true? I would rather say:

Darwin’s central idea was right—widely diverse organisms are related through common ancestry, and natural selection is one important cause of that diversity

Since Darwin, we have uncovered other important causes. In many cases, Biologists debate which cause is “primary.” Part of this is dependent on what we mean be “diversity.” The bare sentence seems to miss this point. What do you think @TedDavis?


(George Brooks) #4

Frankly, I’m not too happy with either version. When we talk about the “cause or causes” of Diversity … my mind keeps bringing me back to:

  1. mutations (which would include the cell’s natural inability to perfectly replicate genetic sequences every time);

and

  1. the tendency of gene pools to branch off and wander into new and independent evolutionary paths due to:

a] unpredictable [not random] geographical separation,
b] changes in mating practices due to unpredictable [not random] changes in preferences and/or genetic reproductive compatibility, and
c] the unpredictable [not random] affects on the vagaries of the ecosystem on the above factors and on
d] the comparative net differences in the number of offspring surviving to reproductive age over any given time period for any given genetic subtype.


(Bill Cole) #5

I have seen these explanations but how the genome gets organized to express these co opted genes is never explained and certainly there is no experimental data that even comes close to validating this. I think we need to agree that Michael Behe has made a very strong argument that has never been strongly contested.

If I asked you to create the DNA sequence from scratch to build a flagellum motor and gave you 50% of the proper sequences you would certainly fail this project if you were held to a trial and error process.

If we are thinking about evolution in the wrong way it is better sooner than later to realize it. I am seeing continuous distancing from the blind watchmaker thesis.


(Peaceful Science) #6

I absolutely contest this. His argument has been entirely invalidated.

To make my point, you can actually trying making the case. Pretty quickly, you will find that there are severe logical errors, and his first definition was directly invalidated by experiments. Moreover, when these were uncovered, Behe changed the definition of IC. This new definition had its own problems, and was also invalidated directly by experiments.

So the question is, what exact definition of IC do you use? Which of the two IC definitions are correct in your opinion, and why? Until we establish what you mean by IC, it will be very difficult to understand why his argument failed in science. I’ve asked @deliberateresult, for example, to explain which IC definition he holds to. He has yet to answer.

Typically the reason for avoiding this question is that ID advocates often do not actually know that there are two IC definitions, and therefore do not know the precise ways in which each experiment has been invalidated by direct experimentation. You could surprise me of course =).

Which of the two IC definitions do you use and why? From there, I’ll show you why it has been not just contested but entirely invalidated by direct experimentation.


(Bill Cole) #7

I really don’t pay attention to the irreducible complexity argument. This in my mind is a cleaver buzz word Behe came up with for the general public.

The issue is, can you build a flagellum with the blind watchmaker mechanism?

Thats the challenge I gave you so you could start thinking about this. From looking at the list of 30 proteins it appears that there are 15 homologies in the bacterial world. That means you need to build 15 proteins or about 50k of DNA sequences need to get organized plus sequence adjustments from the homologous genes.

If I gave you the fastest supercomputer in the world to explore this space you could not begin to solve this problem with trial and error.

This has enormous implications on how life’s diversity really unfolded on earth given the flagellum is only a bacterial molecular machine.

Even though we may not like the ID general philosophical movement, guys like Behe can add significant value in understanding life’s diversity and should be closely listened to.


(George Brooks) #8

No, @Billcole

That is NOT the issue. The issue is…there are Theistic Evolutionists who would be inclined to agree
that God probably ordained and guided the evolution of the flagellum.

Why can’t you accept that? Why do you keep going to the godless Evolution scenario? That’s not what BioLogos is all about…


(Benjamin Kirk) #9

[quote=“Billcole, post:7, topic:26423”]
I really don’t pay attention to the irreducible complexity argument.[/quote]
Then why are you bringing it up here? Why do you write as though there is only one flagellum?

The “blind watchmaker” is a metaphor, not a mechanism. I don’t see any indication that you have even the most basic understanding of biological mechanisms, and your use of a metaphor as a mechanism only confirms this.

I find this stance to be incredibly arrogant. I am supremely confident that Swamidass, who has posted his own work here, has thought about this much, much more than you have.

Perhaps you should do a more thorough search before arrogantly issuing a challenge. You might also specify which flagellum you are writing about.

Please show your work.

How many other flagella are there in nature, again? Which one?

[quote]Even though we may not like the ID general philosophical movement, guys like Behe can add significant value in understanding life’s diversity and should be closely listened to.
[/quote]Bill, you just wrote that you “really don’t pay attention to the irreducible complexity argument.” You just broke my irony meter. How can you contradict yourself so blatantly and quickly?


(Bill Cole) #10

Hi George
I do accept that BioLogos does not take God out of the picture.

What I was taking issue with was Ted’s claim in the op. that natural selection explained most of life’s diversity. I believe that Michael Behe made a great argument against this 20 years ago.

Although Joshua does not agree with Michael Behe’s irreducible complexity argument he stated to Ted that he thought that natural selection was one of several mechanisms.

I am certainly more comfortable with Joshua’s position then Ted’s, however IMHO natural selection explains little more then in specie adaptions. Both SY and Dennis have cited experiments that support natural selection, however the results were limited to bacteria adapting to environmental change.


(George Brooks) #11

@Billcole

I think the problem with your analysis is that you are fixating on the “amazing” exemplars of ingenious genetic design. You don’t have any explanation for all the examples of genetic design that are terribly maladaptive … and almost certainly display examples of “bad intelligence” if God was really interested in showing his handy work.

It is the examples of poor or “barely serviceable” examples of genetic response to Natural Selection that points to God working from his inventory of existing gene pools (that he created)… rather than God making each life form from scratch.

Why would God make a whole range of life form FOSSILS that never actually lived on the Earth?

Or … if you really think all those fossils are from animals that DID exist but were wiped out in a flood, when would God have had the time to make millions of what are being termed “species”? And some with pretty bad adaptations?

Intelligent Design is a perfectly serviceable idea if you don’t try to apply it to ALL life forms… because really there are some terrible genetic compromises out there!

A FINAL THOUGHT: The phrase “Natural Selection explains most of life’s diversity” is quite awkward!

Natural selection ELIMINATES diversity. This I can agree to.

But what TRIGGERS diversity is generation after generation of the following:
A) gene pools being pushed and pulled by constantly varying ecological factors.
B) gene pools being pushed and pulled by constantly varying genetic sequences.
C) gene pools being divided into separated NEW gene pools due to:

i) geographic separation;
ii) changes in mating patterns due to changes in behavior preferences and;
iii) changes in genetically-driven changes in fertility between new genotypes vs. old.

I suppose some people would say I’m splitting hairs … but I’d rather split hairs over
what you mean by “diversity” than some of the other quibbles I’ve been reading this month.

THE QUESTION TO ANSWER: When and Why would God individually make millions of species/kinds since the time of the Flood and Noah’s Ark?

I don’t think you have an answer for that.


(Benjamin Kirk) #12

[quote=“Billcole, post:10, topic:26423”]
I believe that Michael Behe made a great argument against this 20 years ago.[/quote]
Is the evidence consistent with his argument?

[quote]Both SY and Dennis have cited experiments that support natural selection, however the results were limited to bacteria adapting to environmental change.
[/quote]Are all of the experiments that support natural selection limited to bacteria?


(Roger A. Sawtelle) #13

Bill,

I would agree that Darwinian NS does not explain the magnificent diversity of our world past and present, because it has ignored or slighted the power of ecological NS which drives evolution.

Look at the amount of environmental change that has taken place over billions of years. (This is not easy because humans tend to think that our present environment as timeless.) The environment is always changing. The environment is different in one area from another.

God created this magnificent planet with all of its growing diversity as the home for humans (and many other creatures) with our growing diversity. Sadly we try to stultify our diversity and make humans fit into uniformity and conformity.

Darwinian evolutionary overlooks the full range of ecological Natural Selection at its own peril. Ecological NS selection opens our minds to the glorious plan of God and nature.